SoundAway Barrier Open Cell Carpet Underlay, wide Roll, 3/8" x 4.5' x 25', combines a layer of soundproofing barrier and an open cell foam.  This soundproofing composite decouples two rigid surfaces serving as an isolator, sound barrier,  sound absorber and carpet underlay.

SoundAway Premium Barrier Carpet Underlay, wide Roll, 3/8" x 4' x 30', combines a layer of soundproofing barrier and a dense, sound-absorbing, and sound-blocking, closed cell foam.  This soundroofing composite decouples two rigid surfaces serving as an isolator, sound barrier,  sound absorber and a fabulous carpet underlay.